Upswing in Industrial Activity and Infant Mortality during Late 19th Century US

TL;DR

This study investigates how the surge in industrial activity and pollution in late 19th to early 20th century US increased infant mortality, especially among male infants, using census data and gender ratio proxies.

Contribution

It introduces a novel approach using gender ratio proxies to measure infant mortality related to industrial pollution in historical US data.

Findings

Industrial pollution rise increased infant mortality rates.

Male infants were more affected by pollution-related mortality.

Results are consistent across different measures and data aggregation levels.

Abstract

This paper aims to assess the effects of industrial pollution on infant mortality between the years 1850-1940 using full count decennial censuses. In this period, US economy experienced a tremendous rise in industrial activity with significant variation among different counties in absorbing manufacturing industries. Since manufacturing industries are shown to be the main source of pollution, we use the share of employment at the county level in this industry to proxy for space-time variation in industrial pollution. Since male embryos are more vulnerable to external stressors like pollution during prenatal development, they will face higher likelihood of fetal death. Therefore, we proxy infant mortality with different measures of gender ratio. We show that the upswing in industrial pollution during late nineteenth century and early twentieth century has led to an increase in infant mortality. The results are consistent and robust across different scenarios, measures for our proxies, and aggregation levels. We find that infants and more specifically male infants had paid the price of pollution during upswing in industrial growth at the dawn of the 20th century. Contemporary datasets are used to verify the validity of the proxies. Some policy implications are discussed.